Illuminable panel, dial, and pointer structure



April 7, 1942. M. KLEIN ETAL ILLUMINAELE PANEL, DIAL AND POINTER STRUCTURE 2 Sheets-Sheet l Filed Nov. 29, 1938 NAMCM E April 7, 1942. M. KLEIN x-:T AL.

ILLUMINALE PANEL, DIAL AND POINTER STRUCTURE Filed Nov. 29, 1958 2 Sheets-SheeI 2 u: gell Patented Apr. 7, 1942 STATES TINT oFFice STRUCTURE rLLUMrNABLr PANEL, met, AND romana Application November 29,1938, Serial No. 243,044

' 5 Claims. "(fCl. llt-1,29)

The present invention relates to a novel dial and pointer, or panel structure, and, more particularly, to a novel dial and pointer or panel structure adapted for striking illumination.

indicating instruments, usually, are mounted on an instrument board in position to he viewed by an operator seated or otherwise stationed in front of the instrument board.` It is often dimcult from the operators position to properly read such instruments due-to improper lighting` oi the dial of the instrument. Furthermore, when such instruments are mounted, particularly in the dashboards of automobiles, aeroplanes and the like, where the instrument must be read at night, it has been impossible to adequately illuminate the dial pointers so that a quick glance -will enablev a reading oi the instrument and at the same time eliminate undesired glare.

Under present manufacturing practices, when the panel or dial and pointer structures are suiciently illuminated, undesirable shadows are cast in the vehicle or the stray light glares in the eyes of the operator so that his view through thewindshield is seriously impaired.

It is, accordingly, the primary object of the present invention to provide a novel panel or dial structure, which may be adequately illuminated while preventing undesired distribution of light in' the region around and beyond the panel.

A further object of the ,present invention resides in providing an indicia bearing element, particularly adapted to be illuminated by directing rays of light into the body of the element in such a way that the indicia appear luminous.

A further ob'ect of the present invention remally artificially illuminated element with radium treated areas to intensify the artificial illumination of said areas and to serve as a safety factor upon failure of the source of artificial illumination.

Other objects will appear from this description and the appended claims when read in connecv tion with the attached drawings, wherein:

Figure l is a front plan view of a dial blank of the present invention;

Figure 2 is a rear plan View of the dial blank of Figure l after application oi the primary coating.

Figure 3 is a iront plan View of a completed dial made in accordancewith the present invention. v

Figui-e4 is a sectional view taken on line fiof Figure 3. V

Figure 5 is a top plan view of a pointer made in accordance with the present invention;

Figure 6 is a side elevational view of the ,pointer of Figure 5.

Figure l is a sectional view takenon line 1 -i of Figure 5;

Figure 8 is a sectional View taken on line of Figure V5; Figure a is an assembly view in partial section illustrating a preferred manner of using the .dial and pointer of Figures 1-'7;

Figure 10 is a plan'view of a modified form of the present invention;

Figure 11 is an assembly view showing a preferred way of using the dial of Figure 10.

With continued reference to the drawings, wherein like reference numerals are employed to designate the same parts through the several figures of the drawings, numeral lil indicates generally a disk-like dial member illustrating an indicia bearing elem-ent manufactured inacvcordance with the present invention. While a circular dial for an indicating instrument is illustrated, it 'is to be understood that the member 4B may take any desired form and be applied to any desired use without departing from the scope of the present invention.

Dial lll is made of a crystal clear or translucent substance for example, Plexiglas which is an acrylic resin or Lucite which is a polymerized derivative of methacrylic acid. Either 'of dial I0 and preferably a portion .I4 of the rear face adjacent portion I3 the purpose of which will be hereinafter pointed out. 'I'he portion I3 is provided with vertically extending fluting or grooves I5 designed to diffuse the rays of light entering through portion I3, throughout the body of dial III.

The coating I2 on the face of dial I0 is rela.- tively thin and is printed over with a black paint or like opacent material, to form an opaque coating I I except in the area of the markings, figures, etc., which are left white. Certain of these white markings and the numerals and letters may then be treated with radium paint I8 in the usual manner. The coating I2 on the coated portion of the edge and the rear surface is relatively heavy to assure the proper functioning of the dial.

An aperture 2| is provided in the center of dial I0 for the passage of the pointer operating spindle and suitable apertures 22 are provided for the passage of suitable securing elements.

The pointer 23 is also preferably constructed of similar translucent material. The indicating portion 24 of pointer 23 is preferably of. substantially triangular shape in cross-section with a flat f-ace 25 of the triangle serving as the underside. Face 25 is provided along each longitudinal edge with a series of parallel, transverse flutings or grooves 28 and the upper surface is coated with a thin coat 21 of white paint. A radium paint coating 28 may be disposed over the white paint coating, in whole or in part, after the manner of the markings, etc., of the dial.

,The hub 29, tail 3l and balance weight 32 are preferably provided with a. coating 33 of opaque material like that applied to the face of the dial. As a consequence, when the dial and pointer are in assembled relation as in Figure 9, portion 24 will be readily seen against the dark background of dial I0 while tail portion 3|, hub 29 and balance Weight 32 will blend in with the dial background and be relatively invisible.

The use of such indicia bearing elements and pointers is particularly adapted for a system of lighting such as that described in detail and claimed in the copending application of Maximilian Klein and William E. Pfeffer entitled Illuminating indicating instruments, Serial No. 243,045, filed November 29,` 1938. In this system, rays of light from a bulb 35 pass through a bulls-eye lens 36 to reflecting surface 31 of prism 38 and are projected on the fluted edge portion I3 of dial I0 from exit face 39 of prism 38. The portion I3, being clear, the rays of light enter the interior of the body of dial I0. Due to the vertical fluting I5, the rays enter dial I0 in all directions and are diffused throughout the interior of the dial.

These diffused rays of light pass through dial I D and strike the exteriorly coated edges of the dial where each ray is partially reflected in a multiplicity of directions due to the concave, partial reflecting surface provided by the coated edges of the dial. As a consequence, the dial body glows causing unusually sharp illumination of the white markings and figures due to the absorption ofl light by the white coating. The white coating on the edge, rear surface and face of dial I0 further assures the glowing of the dial body, since this portion of the coating absorbs a portion of the light rays and in effect, produces a multiplicity of additional light sources for lighting the markings.

The illumination of the primary markings and figures on the face of the dial is further enhanced due to the fact that radium coating I8 absorbs still further rays of light and due to the inherent characteristics of the radium material in adding further light energy to these markings and figures.

The black coating II furnishes an opaque. dark background, causing the markings and figures to stand out in sharp contrast. As a consequence, the dial markings are brightly illuminated, While undesired glare is eliminated due to the indirect nature of the light rays.

Since the rays of light enter dial I0 at I3, the area vimmediately adjacent thereto normally would receive more light and the numerals in this area ,would be somewhat brighter and diminish the, desired even appearance of the dial. Accordingly, area. I4 on therear of dial I0 may be left free of White paint so that the face coating of white over the corresponding area is lighted by absorption of' the direct light from the light source and is not augmented by reflected light from the rear surface.

Other rays of light are directed across the face of dial I0. These rays strike pointer 23 and are absorbed by the surface coating while others strike the fluting 26 and are diffused throughout the body of the pointer in much the same manner as in the dial.

The radium coating on the dial markings and pointer also serves as an emergency or safety element, should the artificial source of light fail while in service. In this connection, the radium, as is well known, will glow in the dark so` that the instrument is readable although not so readily as when the normal source of illumination is operating,

While the illumination on member I0 is very good if the entire rear face of member I0 is provided with the white coating I2, it has been found that the portion of member I 0 adjacent the Iluted DOrtion I3 is somewhat brighter causing uneven illumination of the markings. It is to eliminate this so-called bright spot that portion I4 is left free of the coating material. It would appear that the elimination of coating l2 over this area permits a portion of the light rays to pass rearwardly through portion I4 into the casing and the lighting of the markings in this area occurs solely due to the absorption of the more intense entering rays by the thin White coating o1' the dial face immediately overlying the portion I4. The provision of this clear portion I4, accordingly, enables the uniform lighting of the markings over the entire dial.

A modification of the' present invention is disclosed in Figures 10 and 1l. In this form of the invention, the same reference numerals will be used to indicate the same parts and a detailed description thereof will be omitted.

The dial Illa of this form of the invention is made up with a perfectly clear central portion 4I and with a clear fluted edge portion I3. The margin of dial face 42 is sandblasted as heretofore described and the edge of dial IU, except portion I3, and the marginal portions of front face 42 and rear surface 43 are provided with a coating 44 of white paint. The marginal coating on face 42 is relatively light as compared to that on the edge and rear surface. The coated margin 44 of face 42 is printed over with opacent material, in the manner heretofore'described, to provide an opaque coating 45 leaving the markings and figures white. Certain of these markings and the figures may then be coated with radium as at I8, in the manner heretofore described.

Dial Ia, constructed as pointed out above, may be mounted on spacers 46 (Figure 1l) and causes the light rays to pass through the body of the dial, as heretofore vpointed out, and the markings in the margin of the dial face glow, as pointed out in connection with the dial of cept at portions thereof, the interruptions of said opaque coating providing indicia, and means-to minimize glare at the interruptions adjacent the source of edge illumination, comprising means to reflect and disperse light into the more remote interruptions. f

2. A non-glaring, illuminable indicia-bearing element, comprising a body of translucent ma.-

Figures 1 to 9. The central portion 4| appears as a lighted eld through which a metallic pointer 41 mounted in front of a. dark faced disk 88 carried by framework F is viewed. l

. A portion of the light rays pass across the rear surface of dial l0, illuminating the area between an opaque disk 48 and dial IIJ and augments the light trom portion dl of the dial. As a consequence, the pointer d1 and any desired name plate or the like (not shown) on disk at, may be read with facility. Ii desired, a reflector may encircle the area between dial lila and dislf. It@ to further enhance the illumination of pointer ti and disk Lit. I

While the present invention has'been described in connection with dials over which pointers moverit is capable of use in connection with illuminated panels or other indicia bearing elements, such as radio panels or like, in which no 'movable pointer is used, the illumination of such panels, which frequently include several sets of indicia, having been found to be highly satisfactory, the indicia standing out vividly on a dark ground.

It will be understood that no shadows are cast terial having a coating of translucent, white paint covering the front and back face except for a small portion of an edge and a small area of the ybacls face adjacent said uncoated edge portion and an opaque coating applied to the front face of said` body over said rst-named coating,y said opaque coating being interrupted at predetermined points to provide indicia.

3. A dial and pointercombination, consisting of a dial having a body of translucent material coated on 'its front face with an opaque material to obscure the reading of the indicia of dials or Y panels, constructed in accordance with the present invention and used as herein disclosed.

The invention may be embodied in other specic forms without departing from the spirit or essential characteristics thereof. 'I'he present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalencyv ofthe claims are therefore intended to be'embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

l. A non-glaring, edge illuminable indiciabearing element, comprising a body of translucent material, a light transmitting coating applied over one side of said body and an opaque coating applied over said rst-named coating exinterrupted atpredetermined points to provide indicia and having a light transmitting coating applied to its rear face, and a pointer comprising an indicating portion, hub and counterweight portion movableover said dial and having a light transmitting coating applied to the indicating portion and an `opaque coating applied to the' hub: and counterweight portion, said dial and pointer cooperating to provide a dial and pointer assembly wherein the indicia on the dial and the indicating portion of the pointer only are adapted for illumination.

4. A pointer for an illuminated dial, comprising a body of translucent material having a hub portion, an indicating portion and a counter` substantially planar light transmitting body!) forming a dial, a smooth unbroken coating of` light colored translucent material on said sur- Aface, an opaque coating of contrasting color over said translucent coating, said opaque coating being provided with discontinuities which expose l portions of said translucent coating to provide l indicia on said dial, and means on an edge por- 

